Peppermint Shrimp Breeding Success & Documentation

[DaJMasta]

After a year and change of off-and-on trying, I had my first juveniles settle out earlier this month. During the run, I took some footage under a low magnification microscope every few days, so I've put together a video of larval development.


I also kept a short log of my configuration and notes while doing it, and it's attached.

My basic setup:
Collect larvae from display with surface skimming larva collector: https://www.reef2reef.com/threads/3d-printed-pelagic-larva-and-egg-collector.1002314/
Raise in 3 Gallon Brute Bucket with 3d printed bits: https://www.thingiverse.com/thing:6436667
Wrap bucket in a seed warming mat heater
Run airline to center of bucket, 1-3 bubbles per second
Occasional (ideally at least weekly) full water changes with siphon screen: https://www.thingiverse.com/thing:6467504
Feeding artemia nauplii several times a day (ideally a small enough quantity that it is not still lingering around at the next feeding) as well as mixed copepods once a day (I fed phyto a couple of times and am wondering if it actually was harmful in my case)
Mostly covered with plexiglass to reduce evaporation, with a dim light on a 14 hour photoperiod

Only got two to settle, the first one at four weeks, the second five days later.

 

[Uncle99]

Wow, that’s not easy….way to go…
I’ve done skunks but not peps…

 

[DaJMasta]

Thanks, though I think they're probably pretty similar in terms of requirements and larval cycle - maybe not timeframe. If you've raised skunk cleaner larvae, peppermint shrimp are probably within reach, and while I've got a vacation coming up, I hope to get some skunk and fire shrimp larvae to try and raise too.

 

[reefluvrr]

Great job

 

[strich]

This is bloody amazing mate, thanks for putting in so much detail and work to share with the community, truly!

How come you advise waiting until there isn't much or any food supply before doing the next feed? I guess just to guard against polluting the water? I wonder if a period of time with low food availability is a partial cause to die offs though. Maybe a constant drip of phyto/pods would be better.

What are your theories around the die offs and what do you think you might try to improve in the future?

I don't have any experience in breeding these guys, but the engineer in me wonders if there would be better survivability if the system were larger. IE maybe connecting the bucket to a host large system to drip water change over a long period plus a phyto constant drip. Basically to broaden the system size but at a slow rate.

 

[DaJMasta]

So I think my next attempt will be without phytoplankton altogether, to throw a wrench in things.

Basically, the phyto does make the food organisms more nutritious, but it also lets them grow, so with a lot of larvae (maybe not Lysmata larvae since they are large and can eat large things), the growth of the brine shrimp nauplii will outpace their own, and could potential injure them or not be edible, all while being less nutritious than the nauplii. So I'd probably add the nauplii alone, and once they run out of egg sack and can't continue to survive (and are not as nutritious for losing it anyway), they seem to sort of get stuck at the surface in small clumps, so I was skimming them out with a cup. There's also a chance my phyto was contaminated (I know it was with different algae, but one may have also had some kind of ciliate).

In terms of quantity, I don't know if I have a good way to put a number to the 'right look' I was aiming for, but basically I would try to feed several times a day (minimum morning and night, but different depending on culture and personal availability), and I'd try to check for density at least one additional time. That way if it looked like a lot from the previous feeding remained, I would only feed a little, while if they look like they cleared everything out, I would feed some extra or at a time of day I don't always. In particular as they grew I was surprised at how quickly they would clean out the place, so extra checking and feeding accordingly certainly helped.

I think larger system volume is how most people do it, but there are a couple reasons I didn't end up going that way (and I've tried some up to ~8G worth of volume).
First off, maintenance. These are buckets on the ground in my room and the fact is that if they're 5G+ buckets, they're enough of a pain to carry, maneuver to drain, and look into that I know I won't be as diligent with my care. A 3G bucket not filled to the brim means I can see to the bottom with a flashlight (provided the bottom is darkened), I can get two water changes out of a 5G bucket and that's usually what I have space for and is convenient to remake.

Second off, even though the dilution factor actually makes for less maintenance, you also then need to fill the volume to a similar prey density, so you've got a lot more food required, a lot more nutrient input, and you sort of end up undoing the help for dilution. I think an ideal scenario would basically be a smaller area for the larvae connected to a larger system volume (basically a sump), but keeping the larvae and food in the smaller area and then doing so gentle enough as to not injure either and still be able to be cleaned easily is not such an easy design requirement.

FWIW, I've also tried raising them with previous attempts with copepods only, and while I could manage to get some to several weeks old, I really think it's a challenge to provide enough that they can catch. The way I see it, copepods are more nutritious, but they're harder to catch and harder to keep on hand in quantity, so I'm sort of using the artemia nauplii for the calories and reasonable vitamin content (egg sack), and then offering some copepods as alternative/diverse foods.

I know dieoffs can be linked to metamorphosis stages, but I don't think I have enough data to know whether mine were, so I'm going to assume it was either water quality or prey density and then keep more records to see if there's some zoea stage metamorphosis that is particularly problematic (like flexion with fish larvae.)

 

[strich]

That's great insight thanks.

There are so many things to test out. I've also always wondered that if you can connect it to a large host system if you can get away with adding in large food sources like a cube of something and a led light on it to attract them to just sit and eat it. The water would stay unfouled due to the constant water change with the host system.
But maybe the larvae not moving due to a static food source causes other problems.

You may have read this paper already but there are some great insights here: https://www.researchgate.net/public..._Lysmata_debelius_under_Sri_Lankan_conditions

 

[althyu]

Wow, that’s not easy….way to go…
I’ve done skunks but not peps…

Wow, you actually got skunks to settle? I thought that those were really hard to keep alive because of a very long larval period.

 

[Uncle99]

Wow, you actually got skunks to settle? I thought that those were really hard to keep alive because of a very long larval period.

They are released formed with appendages and feed right away.

But the grow out was almost half a year.

 

[althyu]

They are released formed with appendages and feed right away.

But the grow out was almost half a year.

What did you feed them until settling, just BBS?

 

[Uncle99]

What did you feed them until settling, just BBS?

No, rotifer enriched with Phyto and selcon for 4 weeks, then slowly, some pulverized flake.

 

[DaJMasta]

A tiny little update: I've now seen one of the new shrimps carrying eggs - not sure if they're fertilized, but the distinct color under the abdomen. They're maybe 25-30mm long now, so close to the smallest size I've seen normally for sale, and at less than 3 months since spawn, they're ready to start another generation. The development speed is staggering!

 

[SteveMM62Reef]

I had them in a 45 gallon, I was getting ready to tear down, when I noticed them. Feed Live Brine Shrimp. Then I remembered the Adults went crazy over ReefRoids. Did a very slow drip, and noticed they were hanging around the outlet. I was not able to get any to adulthood. BTW, the Aquarium was a Reef Aquarium, with some of the Gravel and Live Rock remaining. HOB Filter, which I put a very fine Mesh over the intake, and slowed the flow down.